1. Technical Field
The present invention relates to a vertical cavity surface emitting laser and an atomic oscillator.
2. Related Art
The vertical cavity surface emitting laser (VCSEL) is, for example, used as a light source of the atomic oscillator using coherent population trapping (CPT) which is one of the quantum interference effects.
JP-A-2007-165501, for example, discloses a vertical cavity surface emitting laser including: a columnar (vertical resonator) which is configured with a portion of a first mirror, an active layer, and a second mirror; an electrode which is provided on the first mirror; and an electrode which is provided on the second mirror.
However, in the vertical cavity surface emitting laser disclosed in JP-A-2007-165501, the electrode which is provided on the first mirror is only disposed on one side of the vertical resonator, and thus electric field distribution may be asymmetric with respect to the vertical resonator. When the electric field distribution is asymmetric with respect to the vertical resonator, intensity of laser light emitted from the vertical resonator, for example, may be asymmetric.